Bug/skv konto numbers (#498)

* feat(skattekonto): add overdue transactions handling and split logic

* feat: enhance transaction handling and loading states

- Update BalanceHero component to display last synced date and additional information about Skatteverket updates.
- Refactor BookDirectlyDialog to simplify transaction linking logic and improve UI for transaction selection.
- Revamp InvoiceInboxWorkspace layout for better responsiveness and user experience, including improved skeleton loading states.
- Introduce new loading states for ExtensionWorkspace to match the live layout and improve user feedback during data fetching.
- Implement exchange rate fetching in QuickReviewDialog, ensuring transactions are always processed in SEK with error handling for rate fetching.
- Add structured error handling for unavailable exchange rates in the transaction API.

* feat(skattekonto): add 'Skattekonto – saldo & transaktioner' scope and update authorization checks

* feat: implement reverse charge handling in supplier invoice calculations and UI

app/api/supplier-invoices/route.ts

@@ -132,7 +132,11 @@ export const POST = withRouteContext(
 
     const subtotal = items.reduce((sum, i) => sum + i.line_total, 0)
     const vatAmount = items.reduce((sum, i) => sum + i.vat_amount, 0)
-    const total = Math.round((subtotal + vatAmount) * 100) / 100
+    // Reverse charge: supplier never invoices VAT, so the payable total equals
+    // the net. VAT is still tracked separately (vat_amount) for declarations
+    // and books fiktiv 2614/2645 in the engine, but neither side moves cash.
+    const payableVat = body.reverse_charge ? 0 : vatAmount
+    const total = Math.round((subtotal + payableVat) * 100) / 100
 
     // Representation (BAS 6070–6079): ingående moms is only deductible up to
     // 300 SEK base/person per ML 8 kap. 1 §, and the income-tax deduction was

app/api/transactions/[id]/refresh-exchange-rate/route.ts

@@ -0,0 +1,64 @@
+import { NextResponse } from 'next/server'
+import { withRouteContext } from '@/lib/api/with-route-context'
+import { errorResponse, errorResponseFromCode } from '@/lib/errors/get-structured-error'
+import { fetchExchangeRate } from '@/lib/currency/riksbanken'
+import type { Currency, Transaction } from '@/types'
+
+export const POST = withRouteContext(
+  'transaction.refreshExchangeRate',
+  async (_request, ctx, { params }: { params: Promise<{ id: string }> }) => {
+    const { id } = await params
+    const { supabase, companyId, log, requestId } = ctx
+
+    const { data: transaction, error: fetchError } = await supabase
+      .from('transactions')
+      .select('*')
+      .eq('id', id)
+      .eq('company_id', companyId)
+      .single<Transaction>()
+
+    if (fetchError || !transaction) {
+      return errorResponseFromCode('TX_CATEGORIZE_TX_NOT_FOUND', log, { requestId })
+    }
+
+    // No-op for SEK transactions, or when the rate is already cached.
+    if (
+      transaction.currency === 'SEK' ||
+      (transaction.amount_sek != null && transaction.exchange_rate != null)
+    ) {
+      return NextResponse.json({ data: transaction })
+    }
+
+    const rate = await fetchExchangeRate(transaction.currency as Currency, new Date(transaction.date))
+    if (!rate) {
+      return errorResponseFromCode('TX_EXCHANGE_RATE_UNAVAILABLE', log, {
+        requestId,
+        details: { currency: transaction.currency, date: transaction.date },
+      })
+    }
+
+    const amountSek = Math.round(transaction.amount * rate.rate * 100) / 100
+
+    const { data: updated, error: updateError } = await supabase
+      .from('transactions')
+      .update({
+        amount_sek: amountSek,
+        exchange_rate: rate.rate,
+        exchange_rate_date: rate.date,
+      })
+      .eq('id', id)
+      .eq('company_id', companyId)
+      .is('journal_entry_id', null)
+      .select('*')
+      .single<Transaction>()
+
+    if (updateError || !updated) {
+      return errorResponse(updateError ?? new Error('Failed to persist exchange rate'), log, {
+        requestId,
+      })
+    }
+
+    return NextResponse.json({ data: updated })
+  },
+  { requireWrite: true },
+)